U.S. patent number 8,711,977 [Application Number 13/083,675] was granted by the patent office on 2014-04-29 for method for transmitting a signal.
This patent grant is currently assigned to Intel Mobil Communications GmbH. The grantee listed for this patent is Tobias Scholand. Invention is credited to Tobias Scholand.
United States Patent |
8,711,977 |
Scholand |
April 29, 2014 |
Method for transmitting a signal
Abstract
The method includes providing a stream of data to be
transmitted, and processing the data by means of channel coding
with a time-varying code rate, thereby generating a stream of
channel coded data. The method further includes forming succeeding
transmission time intervals and distributing the channel coded data
on the transmission time intervals, and adjusting a transmission
power of the signal to be transmitted by timely positioning a
transmission power slope between two succeeding transmission time
intervals so that the transmission power slope is contained
completely within one transmission time interval of the two
transmission time intervals, wherein the one transmission time
interval comprises a lower nominal code rate or a lower nominal
transmission power than the other one of the two transmission time
intervals.
Inventors: |
Scholand; Tobias (Muelheim,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Scholand; Tobias |
Muelheim |
N/A |
DE |
|
|
Assignee: |
Intel Mobil Communications GmbH
(Neubiberg, DE)
|
Family
ID: |
46875322 |
Appl.
No.: |
13/083,675 |
Filed: |
April 11, 2011 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20120257686 A1 |
Oct 11, 2012 |
|
Current U.S.
Class: |
375/299; 375/349;
375/260; 375/267; 375/347 |
Current CPC
Class: |
H04L
1/0009 (20130101); H04W 52/262 (20130101) |
Current International
Class: |
H04L
27/00 (20060101) |
Field of
Search: |
;375/295,260,267,299,347,349 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"3GPP TS 25.101: 3rd Generation Partnership Project; Technical
Specification Group Radio Access Network; User Equipment Radio
Transmission and Reception (Release 8)", 3rd Generation Partnership
Project, v. 8.11.0, Jun. 2010, p. 1-215. cited by applicant .
"3GPP TS 25.321: 3rd Generation Partnership Project; Technical
Specification Group Radio Access Network; User Equipment Radio
Transmission and Reception (Release 9)", 3rd Generation Partnership
Project, v. 9.3.0, Jun. 2010, p. 1-192. cited by applicant.
|
Primary Examiner: Timory; Kabir A
Attorney, Agent or Firm: Eschweiler & Associates,
LLC
Claims
What is claimed is:
1. A method for transmitting a signal in a mobile communication
system, comprising: providing a stream of data to be transmitted;
processing the data by channel coding with a time-varying code
rate, thereby generating a stream of channel coded data; forming
succeeding transmission time intervals and distributing the channel
coded data on the transmission time intervals; and adjusting a
transmission power of the signal to be transmitted by timely
positioning a transmission power slope between two succeeding
transmission time intervals so that the transmission power slope is
contained completely within one transmission time interval of the
two transmission time intervals, wherein the one transmission time
interval comprises a lower nominal code rate or a lower nominal
transmission power than the other one of the two transmission time
intervals, wherein one of the two succeeding transmission time
intervals comprises a first nominal code rate or a first nominal
transmission power and the other one of the two succeeding
transmission time intervals comprises a second nominal code rate or
a second nominal transmission power, respectively, and wherein the
second nominal code rate or the second nominal transmission power
is greater than the first nominal code rate or the first nominal
transmission power, respectively, the method further comprising:
adjusting the transmission power slope if the difference between
the first nominal code rate and the second nominal code rate or
between the first nominal transmission power and the second nominal
transmission power is above a predetermined threshold.
2. The method according to claim 1, wherein the time duration of a
transmission power slope is below 50 .mu.s.
3. The method according to claim 1, wherein one of the two
succeeding transmission time intervals comprises a first nominal
code rate or a first nominal transmission power and the other one
of the two succeeding transmission time intervals comprises a
second nominal code rate or a second nominal transmission power,
respectively, and wherein the second nominal code rate or the
second nominal transmission power is greater than the first nominal
code rate or the first nominal transmission power, respectively,
the method further comprising: adjusting the transmission power if
the second nominal code rate or the second nominal transmission
power is above a predetermined threshold value.
4. The method according to claim 1, wherein the method is carried
out in a transmitter comprising a baseband section and a radio
frequency section, the method further comprising: determining the
timely position of the transmission power slope in the baseband
section.
5. The method according to claim 4, further comprising: determining
the timely position of the transmission power slope according to a
varying nominal code rate or a varying nominal transmission
power.
6. The method according to claim 4, wherein the baseband section
generates a baseband signal and the transmission power slope is
included in the baseband signal.
7. The method according to claim 1, wherein the method is carried
out in a transmitter comprising a baseband section and a radio
frequency section, the method further comprising: determining the
timely position of the transmission power slope in the radio
frequency section.
8. The method according to claim 7, further comprising: determining
the timely position of the transmission power slope according to a
varying nominal code rate or a varying nominal transmission
power.
9. The method according to claim 1, wherein the mobile
communication system operates according to a 3G High Speed Packet
Access (HSPA) standard.
10. The method according to claim 1, wherein the mobile
communication systems operates according to a 3G Long Term
Evolution (LTE) standard.
11. A method for transmitting a signal in a mobile communication
system, comprising: providing a stream of data to be transmitted;
processing the data by channel coding with a time-varying code
rate, thereby generating a stream of channel coded data; forming
succeeding transmission time intervals and distributing the channel
coded data on the transmission time intervals; adjusting a
transmission power of the signal to be transmitted by timely
positioning a transmission power slope between two succeeding
transmission time intervals so that the transmission power slope is
contained completely within one trans-mission time interval of the
two transmission time intervals, wherein the one transmission time
interval comprises a lower nominal code rate or a lower nominal
transmission power than the other one of the two transmission time
intervals; and adjusting the transmission power according to the
following: if a nominal code rate or a nominal transmission power
is to be increased from a first value in a first transmission time
interval to a second value in a second transmission time interval,
wherein the second value is greater than the first value, then a
transmission power increase will completely occur within the first
transmission time interval, and if the nominal code rate or the
nominal transmission power is to be decreased from a third value in
a first transmission time interval to a fourth value in a second
transmission time interval, wherein the fourth value is less than
the third value, then a transmission power decrease will completely
occur within the second transmission time interval.
12. A transmitter for transmitting a signal in a mobile
communication system, comprising: a channel coding unit configured
to receive a stream of data to be transmitted and perform a channel
coding operation with a time-varying code rate; and a transmission
power adjusting unit configured to adjust a transmission power of
the signal to be transmitted by timely positioning a transmission
power slope between two succeeding transmission time intervals so
that the transmission power slope is contained completely within
one transmission time interval of the two transmission time
intervals, wherein the one transmission time interval comprises a
lower nominal code rate or a lower nominal transmission power than
the other one of the two transmission time intervals, wherein one
of the two succeeding transmission time intervals comprises a first
nominal code rate or a first nominal transmission power and the
other one of the two succeeding transmission time intervals
comprises a second nominal code rate or a second nominal
transmission power, respectively, and wherein the second nominal
code rate or the second nominal transmission power is greater than
the first nominal code rate or the first nominal transmission
power, respectively, and wherein the transmission power adjusting
unit is configured to timely position the transmission power slope
only if the difference between the first nominal code rate and the
second nominal code rate or between the first nominal transmission
power and the second nominal transmission power is above a
predetermined threshold.
13. The transmitter according to claim 12, wherein the transmission
power adjusting unit is configured to adjust the time duration of
the transmission power slope to below 50 .mu.s.
14. The transmitter according to claim 12: wherein one of the two
succeeding transmission time intervals comprises a first nominal
code rate and the other one of the two succeeding transmission time
intervals comprises a second nominal code rate, and wherein the
second nominal code rate is greater than the first nominal code
rate, and wherein the transmission power adjusting unit is
configured to timely position the transmission power slope only if
the second nominal code rate is above a predetermined threshold
value.
15. The transmitter according to claim 12, further comprising: a
baseband section and a radio frequency section, wherein the channel
coding unit and the transmission power adjusting unit are arranged
in the baseband section.
16. The transmitter according to claim 15, wherein the transmission
power adjusting unit is configured to determine the timely position
of the transmission power slope according to the timely varying
nominal code rate or to the timely varying nominal transmission
power.
17. The transmitter according to claim 15, wherein the baseband
section is configured to generate a baseband signal, and the
transmission power adjusting unit is configured to incorporate the
transmission power slope into the baseband signal.
18. The transmitter according to claim 12, further comprising: a
baseband section and a radio frequency section, wherein the channel
coding unit is arranged in the baseband section and the
transmission power adjusting unit arranged in the radio frequency
section.
19. The transmitter according to claim 18, wherein the transmission
power adjusting unit is configured to determine the timely position
of the transmission power slope according to a varying nominal code
rate or a varying nominal transmission power.
Description
FIELD
The present invention relates to a method for transmitting a signal
in a mobile communication system and a transmitter for transmitting
a signal in a mobile communication system.
BACKGROUND
In a mobile communication system the data rate can be adapted
dynamically for efficiency reasons. The power of the transmitted
signal also changes due to the data rate as every successfully
transmitted bit must be paid for with a certain amount of
transmitted energy. In a transmitter of a mobile communication
system channel coding is usually employed, providing bit redundancy
for the purpose of error protection. Channel coding can be employed
with timely varying code rates. As very high code rates result in
very low redundancy a problem arises in particular for certain
modulation schemes when any amplitude variation is present in the
transmitted signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings are included to provide a further
understanding of embodiments and are incorporated in and constitute
a part of this specification. The drawings illustrate embodiments
and together with the description serve to explain principles of
embodiments. Other embodiments and many of the intended advantages
of embodiments will be readily appreciated as they become better
understood by reference to the following detailed description.
FIG. 1 shows a flow diagram of a method for transmitting a signal
in a mobile communication system according to an embodiment;
FIG. 2 shows a time diagram of a nominal transmission power
according to a transport format change (a) and a variation of the
transmission power (b);
FIG. 3 shows a schematic block representation of a transmitter for
transmitting a signal in a mobile communication system according to
an embodiment; and
FIG. 4 shows a schematic block representation of a transmitter for
transmitting a signal in a mobile communication system.
DETAILED DESCRIPTION
The aspects and embodiments are described with reference to the
drawings, wherein like reference numerals are generally utilized to
refer to like elements throughout. In the following description,
for purposes of explanation, numerous specific details are set
forth in order to provide a thorough understanding of one or more
aspects of the embodiments. It may be evident, however, to one
skilled in the art that one or more aspects of the embodiments may
be practiced with a lesser degree of the specific details. In other
instances, known structures and elements are shown in schematic
form in order to facilitate describing one or more aspects of the
embodiments. It is to be understood that other embodiments may be
utilized and structural or logical changes may be made without
departing from the scope of the present invention.
In addition, while a particular feature or aspect of an embodiment
may be disclosed with respect to only one of several
implementations, such feature or aspect may be combined with one or
more other features or aspects of the other implementations as may
be desired and advantageous for any given or particular
application. Furthermore, to the extent that the terms "include",
"have", "with" or other variants thereof are used in either the
detailed description or the claims, such terms are intended to be
inclusive in a manner similar to the term "comprise". The terms
"coupled" and "connected", along with derivatives may be used. It
should be understood that these terms may be used to indicate that
two elements co-operate or interact with each other regardless
whether they are in direct physical or electrical contact, or they
are not in direct contact with each other. Also, the term
"exemplary" is merely meant as an example, rather than the best or
optimal. The following detailed description, therefore, is not to
be taken in a limiting sense, and the scope of the present
invention is defined by the appended claims.
The methods and apparatuses as described herein are utilized as
part of and for mobile communication systems, in particular systems
operating according to one of the 3G mobile communication
standards. More particularly, the mobile communication systems may
employ one or more of the Universal Mobile Telecommunications
Systems (UMTS) Standard or the High Speed Packet Access (HSPA)
Standard or the Long Term Evolution (LTE) Standard.
The method and apparatuses as described herein may be embodied in
transmitters like base-stations or relay-stations as well as in
mobile phones, hand-held devices or other kinds of mobile radio
transmitters. The described apparatuses may be employed to perform
methods as disclosed herein, although those methods may be
performed in any other way as well.
The methods and apparatuses as described herein may also be
utilized with any sort of antenna configurations employed within
the mobile communication system. In particular, the concepts
presented herein are applicable to mobile communication systems
employing more than one transmit and/or receive antenna and in
particular an arbitrary number of transmit and/or receive
antennas.
Referring to FIG. 1, there is shown a flow diagram of a method for
transmitting a signal in a mobile communication system according to
an embodiment. The method comprises providing a stream of data to
be transmitted at s1, and processing the data by means of channel
coding with a time-varying code rate, thereby generating a stream
of channel coded data at s2. The method further comprises forming
succeeding transmission time intervals and distributing the channel
coded data on the transmission time intervals at s3, and adjusting
a transmission power of the signal to be transmitted by timely
positioning a transmission power slope between two succeeding
transmission time intervals so that the transmission power slope is
contained completely within one transmission time interval of the
two transmission time intervals, wherein the one transmission time
interval comprises a lower nominal code rate or a lower nominal
transmission power than the other one of the two transmission time
intervals at s4.
According to an embodiment of the method of FIG. 1, adjusting the
transmission power is performed as follows. The transmission power
slope can either be a transmission power increase or a transmission
power decrease between two succeeding transmission time intervals.
If the nominal code rate or the nominal transmission power is to be
increased from a relatively low value in a first trans-mission time
interval to a relatively high value in a second transmission time
interval, then a transmission power increase will completely occur
within the preceding first transmission time interval, and if the
nominal code rate or the nominal transmission power is to be
decreased from a relatively high value in a first transmission time
interval to a relatively low value in a second transmission time
interval, then a transmission power decrease will completely occur
within the succeeding second transmission time interval.
The term "nominal" as used in the foregoing within the terms
"nominal code rate" or "nominal transmission power" is intended to
be similar to the terms "intended", "pre-defined",
"pre-determined", or "pre-calculated". For any given transmission
time interval a so-called transport format is chosen beforehand
which defines certain parameters or values of parameters of the
transmission time interval as, for example, the channel coding, the
modulation, or the transmission power. These parameters or values
or at least some of them or all of them can be defined to be
constant throughout the transmission time interval or at least
constant throughout particular slots of the transmission time
interval. The transport format can be chosen or selected by the
baseband section of the transmitter of the communication unit.
It is one essential advantage of the method of FIG. 1 that it
guarantees an essentially steady and constant transmission power
level throughout the transmission time interval which carries data
of a relatively high nominal code rate and corresponding low bit
error redundancy. This transmission time interval is essentially
free of too high power level variations. As a consequence, even for
particular modulation schemes, it will be an easy task for a
channel decoder at a receiver's site to decode the incoming channel
coded data.
According to an embodiment of the method of FIG. 1, the method is
also applied in situations in which one of the two adjacent
transmission time intervals is virtually empty, i.e. being a
transmission time interval in which no transmission occurs or no
data are transmitted. In other words one can say that such a
transmission time interval can be treated as a transmission time
interval having low, namely zero, nominal code rate or low, namely
zero, nominal transmission power.
It is to be noted that the method of FIG. 1 contains an alternative
for deciding about the timely positioning, namely either the one
transmission time interval comprises a lower nominal code rate or a
lower nominal transmission power. It should be stated that in a
practical implementation it might be easier to implement the second
alternative, namely to look at the nominal transmission power. In
most cases the result will be the same as would have been when
taking the first alternative. However, one advantage can be that
the implementation can be easier as the nominal transmission power
is in any case known in the radiofrequency section of the
transmission, whereas the nominal code rate is not necessarily
known in the radiofrequency section and must be transmitted to the
radiofrequency section in case of the first alternative.
According to an embodiment of the method of FIG. 1, the time
duration of a transmission power slope is made below 50 .mu.s, more
particularly below 40 .mu.s, and more particularly below 30 .mu.s.
In an embodiment presented below the duration will be about 25
.mu.s. This value can be defined such that it relates to a power
step between certain values of percentage of the nominal upper
power level like, for example, 10% (5%) of the upper power level as
a low value and 90% (95%) of the upper power level as a high
value.
A mobile communication system functioning according to one of the
3G standards has to deal with dynamic data rates requested by the
application layer using packet-switched (PS) connection. The lower
layers down to the physical layer also adapt their data rates
dynamically for efficiency reasons (e.g. cell capacity, power
consumption etc.). The adaptation of the data rate can be done by
the physical layer once per transmission time interval while these
transmission time intervals are transmitting seamless in time.
In general the physical layer consists of a baseband and a radio
frequency component. For a given transmission time interval the
baseband chooses a transport format according to the instantaneous
data rate. The transport format defines the channel coding or
modulation and the transmit power. By this the quality of service
like block error rate can be made approximately independent from
the instantaneous data rate. The generated baseband signal is
afterwards transmitted by the radio frequency component with the
previous calculated transmit power. Therefore, the radio frequency
component has to change the transmit power for every transmission
time interval.
The radio frequency component can, however, not change the transmit
power instantaneously. Since high data rates like those used in
high speed packet access (HSPA) result in power changes of more
than 20 dBm, the real change of the transmit power can easily make
the reception of the effected transmission time intervals
impossible. This results in lower throughput and worse user
experience in dynamic data rate packet-switched connections.
In a mobile communication system working according to one of the 3G
standards, requirements of the radio frequency component are
defined about e.g. the error vector magnitude (EVM) in order to
guarantee the quality of the transmitted signal. Any unintentional
change in transmit power could cause these requirements to fail.
Since the radio frequency component can not instantaneously change
the transmission power, transient periods are given in which the
transmission power is changed from one value to the other. During
these transient periods no requirements like EVM are made and the
radio frequency component is allowed to change the transmission in
principle with an arbitrary slope. By this it is guaranteed that
the transmission time interval is essentially unaffected by the
power change.
Referring to FIGS. 2a and 2b, there is shown time diagrams: one of
a nominal transmission power of transport format change (FIG. 2a),
and the other a time-dependent real or effective transmission power
(FIG. 2b) according to an embodiment. FIG. 2a represents a typical
HSUPA transport format (E-TFC) change scenario. In this embodiment
the transmission time interval (TTI) has a length of 2 ms and is
divided in 3 slots with a length of 2560 bits each. For each TTI a
special E-TFC selection procedure is performed, setting particular
parameters for the transport block size, the error protection
scheme, the coding rate, the modulation etc. These parameters are
listed in tables together with integer E-TFCI values, each one of
them designating a particular set of parameters. In addition, the
amount of transmission power required to transmit a given E-TFC is
calculated. This calculated transmit power is shown in FIG. 2a. The
power of the up-link control channel DPCCH is only driven by the
inner loop power control (ILPC) while the power of the data
carrying up-link EDCH channel also changes due to the transport
format change. The number of data bits per transmission time
interval is given as transport block size. In the figure the first
transmission time interval (E-TFCI=0) on the left (only two slots
are shown) has a transport block size of 18 data bits changing to a
transport block size of 22996 data bits in the second transmission
time interval (E-TFCI=124), and thereafter changing back to a
transport block size of 18 data bits in the third transmission time
interval (only one slot is shown). The transmit power mainly scales
with the transport block size since the data bits must be paid for
with a certain amount of transmitted energy. This results in a
calculated transmit power change of .+-.20 dBm or even more than
that.
The mobile communication system as used in the scheme of FIGS. 2a
and 2b is able to apply channel coding with very high code rates
offering very low redundancy. In one embodiment the 3G high speed
up-link packet access (HSUPA) uses 4PAM modulation with code rates
up to R=0.9991. Thus, the available redundancy covers only 0.09% of
the modulated bits. The reception of a 4PAM modulated signal
becomes unreliable or even impossible when any amplitude error is
present in the corresponding transmission time interval like that
shown in FIGS. 2a and 2b.
Therefore, the position of the transmission power slope is adapted
to the baseband signal coding or modulation used in the effected
transmission time intervals. FIG. 2b shows the real or effective
transmission power. As shown in FIG. 2b, one aspect of this
embodiment is that the position of the transmission power slopes is
timely positioned in transmission time intervals having stronger
coding corresponding to lower nominal code rates. The code rate of
the two adjacent transmission time intervals is R=0.175 whereas the
code rate of the intermediate transmission time interval is
R=0.9991.
For HSUPA smaller transport blocks always have stronger coding or
modulation. Hence, one can assume that for every transport format
change, causing high transmit power change, a transmission time
interval with strong coding or modulation is present. Otherwise
there would be no change in transport block size and subsequent
transmit power. In FIG. 2b the transmission power slope is
positioned in the left TTI for the first transport format change
and positioned in the right TTI for the second transport format
change. In addition it is shown in FIG. 2b that the duration of the
transmission power slopes is about 25 .mu.s. In particular it can
be defined that this value relates to a power step between 10% (5%)
and 90% (95%) of the upper power level. As a result, all
transmission time intervals in FIG. 2b above can be received and
decoded successfully and no throughput degradation is observed. In
addition the presented solution fulfills the 3GPP requirements
since the transmission power is still adjusted within the transient
period.
According to an embodiment of the method of FIG. 1, the timely
positioning of the transmission power slope according to step s4
can also be coupled to a condition. For example, it can be
determined that one of the two succeeding transmission time
intervals comprises a relatively low nominal code rate and the
other one of the two succeeding transmission time intervals
comprises a relatively high nominal code rate and that the timely
positioning of the transmission power slope is performed only in a
situation in which the difference between the relatively low
nominal code rate and the relatively high nominal code rate is
above a certain predetermined threshold. Another possible condition
for performing the step s4 can be that the relatively high value of
the nominal code rate is above a certain predetermined threshold
value. It is also possible that both above-defined conditions can
be added together. If the condition or the conditions are not
fulfilled, then the transmission power change can be done according
to any other method within the frame of the requirements of the
corresponding 3G standard.
According to an embodiment of the method of FIG. 1, the method is
carried out in a transmitter comprising a baseband section and a
radio frequency section, and the method further comprises
determining the timely position of the transmission power slope in
the baseband section. According to an embodiment thereof,
determining the timely position of the transmission power slope is
performed according to the timely varying nominal code rate or the
timely varying nominal transmission power. Furthermore, it is also
possible that the baseband section generates a baseband signal and
the transmission power slope is included or incorporated within the
baseband signal.
According to an embodiment of the method of FIG. 1, the method is
carried out in a transmitter comprising a baseband section and a
radio frequency section and the method further comprises
determining the timely position of the transmission power slope in
the radio frequency section. Within this embodiment it is also
possible that the timely position of the transmission power slope
is determined according to the timely varying nominal code rate or
the timely varying nominal transmission power.
According to an embodiment of the method of FIG. 1, the mobile
communication system functions according to a 3G High Speed Packet
Access (HSPA) standard.
According to an embodiment of the method of FIG. 1, the mobile
communication system functions according to a 3G Long Term
Evolution (LTE) standard.
Referring to FIG. 3, there is shown a schematic block
representation of a transmitter for transmitting a signal in a
mobile communication system. The transmitter 10 shows a channel
coding unit 1 configured to receive a stream of data and perform a
channel coding operation with a time-varying code rate. The
transmitter 10 also comprises a transmission power adjusting unit 2
configured to adjust a transmission power of the signal to be
transmitted by timely positioning a transmission power slope
between two succeeding transmission time intervals so that the
transmission power slope is contained completely within one
transmission time interval of the two transmission time intervals,
wherein the one transmission time interval comprises a lower
nominal code rate or a lower nominal transmission power than the
other one of the two transmission time intervals.
According to an embodiment of the transmitter of FIG. 3, the
transmission power adjusting unit 2 is configured to adjust the
time duration of the transmission power slope to below 50 .mu.s,
more particularly 40 .mu.s, and more particularly 30 .mu.s.
Regarding the definition of the time duration, reference is made to
the above.
According to an embodiment of the transmitter of FIG. 3, the
transmission power adjusting unit 2 is configured to perform the
step of timely positioning the transmission power slope only under
a predefined condition. In particular, it can be assumed that one
of the two succeeding transmission time intervals comprises a
relatively low nominal code rate and the other one of the two
succeeding transmission time intervals comprises a relatively high
nominal code rate. The condition can be such that the difference
between the relatively low nominal code rate and the relatively
high nominal code rate is above a certain predetermined threshold.
The transmission power adjusting unit is configured to timely
position the transmission power slope according to other
requirements like the general requirements as set in the 3G
standard if the condition is not fulfilled. Alternatively, or in
addition thereto, the transmission power adjusting unit is
configured to perform the timely positioning only under the
condition that the relatively high value of the nominal code rate
is above a certain predetermined threshold value, otherwise
following other requirements like 3G standard requirements.
According to an embodiment of the transmitter of FIG. 3, the
transmitter 10 comprises a baseband section and a radio frequency
section, and the channel coding unit 1 and the transmission power
adjusting unit 2 are arranged in the baseband section. According to
an embodiment thereof, the transmission power adjusting unit 2 is
configured to determine the timely position of the transmission
power slope according to the timely varying nominal code rate or to
the timely varying nominal transmission power. Moreover, it can be
provided that the baseband section is configured to generate a
baseband signal, and the transmission power adjusting unit 2 is
configured to incorporate the transmission power slope into the
baseband signal.
According to an embodiment of the transmitter of FIG. 3, the
transmitter 10 comprises a baseband section and a radio frequency
section, and the channel coding unit is arranged in the baseband
section and the transmission power adjusting unit 2 is arranged in
the radio frequency section.
According to an embodiment thereof, the transmission power
adjusting unit 2 is configured to determine the timely position of
the transmission power slope according to the timely varying
nominal code rate or to the timely varying nominal transmission
power.
According to one embodiment of the transmitter of FIG. 3, the
channel coding unit 1 is a convolutional coder or a turbo
coder.
Referring to FIG. 4, there is shown a schematic block
representation of a transmitter for transmitting a signal in a
mobile communication system according to an embodiment. The
transmitter 20 comprises a baseband section 21 comprising a channel
coding section 21.1 configured to channel code a stream of date
with a time-varying code rate. The transmitter 20 further comprises
a transmission power adjusting unit (TPAU) 22 configured to adjust
a transmission power of the signal to be transmitted by timely
positioning a transmission power slope between two succeeding
transmission time intervals so that the transmission power slope is
contained completely within one transmission time interval of the
two transmission time intervals, wherein the one transmission time
interval comprises a lower nominal code rate or a lower nominal
transmission power than the other one of the two transmission time
intervals. The transmitter 20 further comprises a radio frequency
section 23 coupled to the baseband section 21 to receive therefrom
a stream of channel coded date.
According to an embodiment of the transmitter of FIG. 3, the
transmission power adjusting unit 22 is part of the baseband
section 21. According to an embodiment thereof, the transmission
power adjusting unit 22 is configured to incorporate the
transmission power slope into the baseband signal. Furthermore, the
transmission power adjusting unit 22 can be configured to determine
the timely position of the transmission power slope according to a
timely varying nominal code rate or to a timely varying nominal
transmission power.
According to an embodiment of the transmitter of FIG. 3, the
transmission power adjusting unit 22 is part of the radio frequency
section 23. According to an embodiment thereof, the transmission
power adjusting unit 22 is configured to determine the timely
position of the transmission power slope according to the timely
varying nominal code rate or to the timely varying nominal
transmission power.
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